December 2016

Cooperative Extension Service

Bourbon County

603 Millersburg Rd

Paris, KY 40361

(859) 987-1895

Fax: (859) 987-3120

bourobn.ca.uky.edu

Woody trees and shrubs may exhibit decline resulting from

the stresses that can occur during their lives. Stress may be the

result of improper plant or site selection, incorrect planting or

maintenance practices, or poor soil conditions. Injury from

equipment, weather, or chemicals can also lead to stress and

decline. In addition, biological stresses such as diseases,

insects, and wildlife could result

in stress and decline of woody

ornamentals. Symptoms of

stress and decline include

dieback (Figure 1), leaf scorch,

stunting, premature fall color or

leaf drop, production of water

sprouts or suckers (Figure 2),

and signs of disease or insects.

Typically, one or more primary

stresses cause deterioration of

plant health, followed by

secondary pathogens and/or insects that further decline or

destroy plants. Determining causes of decline requires careful

examination of plants and growing sites, as well as knowledge

of site history. Nevertheless, diagnoses

may be difficult, as the original cause(s)

of plant stress may be obscure or no

longer present. For more information on

stress and decline in woody plants and

related disease problems, review the

publication Stress and Decline in Woody

Plants (ID-50).

Additional Information

Stress and Decline in Woody Plants (ID-50)

Wood decay leads to loss of tree vigor

and vitality, resulting in decline,

dieback, and structural failure. Wounds

play an important part in this process

since they are the primary point of entry

for wood decay pathogens. While other

factors may also result in decline and

dieback, the presence of wounds and/or

outward signs of pathogens provides

confirmation that wood decay is an

underlying problem. Wounds and wood

decay reduce the ability of trees to support themselves.

Wounds may result from numerous sources such as lawn

equipment (Figure 1), pruning, vehicles, herbicides, insects,

wildlife, weather, or objects that girdle or embed in trunks or

branches (Figure 2). Once stress or damage from wounds

occurs, fungal decay pathogens may enter plants to cause

further damage. During rainy seasons and moderate

temperatures, many wood decay fungi produce visible

reproductive structures, such as shelf-like fungal bodies

(Figure 3) or mushrooms.

Additional Information

Tree Wounds – Invitations to Wood Decay Fungi (PPFS-OR-W-01)

Plant Pathology Publications (Website)

F or more information on tree wounds and related disease problems, including symptoms, causes,

prevention, and treatment, review the publication Tree Wounds – Invitations to Wood Decay Fungi

(PPFS-OR-W-01)

By Kimberly Leonberger, Extension Associate and Nicole Ward Gauthier, Extension

Plant Pathologist

Figure 1: Dieback is a common

symptom of stress. (Photo: John

Hartman, UK)

Figure 2: Water sprouts or suckers may result from

severe stress. (Photo: Daniel Herms, The Ohio

State University, Bugwood.org))

Figure 1: Lawn equipment

damage to the base of a tree.

(Photo: Cheryl Kaiser, UK)

Figure 2: Wire from stakes and

fences creates wounds and can lead

to girdling. (Photo: Nicole Ward

Gauthier, UK)

Figure 3: When weather conditions

are favorable, the shelf-like fungal

fruiting structures of some wood

decay pathogens may be visible.

(Photo: Joseph O’Brien, U.S. Forest

Service, Bugwood.org)

Leaf Scorch and Winter Drying of

Woody Plants

Leaf scorch occurs whenever water needed for growth and

health of plant foliage is lost from leaves faster than it can

be replaced from soil. Any factor that interferes with uptake

or movement of water

through plants cause water

deficiency in leaves. While

symptoms are often due to

unfavorable environmental

conditions, leaf scorch can

also result from fungal or

bacterial disease. Leaf

scorch symptoms may

occur on one branch, one

side of a plant, or over an

entire plant. Premature

defoliation may occur, and small twigs or branches may die

back when exposed to water stress or drought. Upper

branches often exhibit the most prominent symptoms.

Leaves of deciduous plants may initially turn yellow and

develop a scorched appearance between leaf veins or along

the margins (Figure 1). Needles of evergreens first turn

brown at the tips, and over time, the brown coloration

progresses towards bases of needles (Figure 2). Broadleaf

and needled evergreens may also be subject to a condition

known as winter drying, which produces symptoms similar

to leaf scorch. Affected leaves dry out and turn brown along

margins or at tips (Figure 3). The plant may develop an

overall wilted appearance. Winter drying may also lead to

dieback of twigs. Symptoms may not become apparent until

late winter or early spring.

For more information on leaf scorch and winter drying of

woody plants and related disease problems, review the

publication Leaf Scorch and Winter Drying of Woody Plants.

Additional Information

Leaf Scorch and Winter Drying of Woody Plants(PPFS

-OR-W-17)

By Kimberly Leonberger, Extension Associate, and

Nicole Ward Gauthier, Extension Plant Pathologist.

Genetically Engineered Crops – A Review of

Concerns and Benefits

The manipulation of the genetic make-up of crops raises

numerous concerns and questions for many consumers. Are

they safe? What are the benefits of GMOs? This publication

aims to provide an unbiased review of the concerns and

benefits of genetically engineered crops (GE crops, also

called GMOs) based on the research available on the topic.

Genetically Engineered Crops – A Review of Concerns and

Benefits (PPFS-MISC-07) is a summary document of the

publication Genetically Engineered Crops – Emerging

Opportunities (PPA-47), which provides additional

information on this topic.

For additional publications on genetically modified crops,

fungicide resistance, or diseases, visit the UK Plant

Pathology Extension Publications webpage.

By Kim Leonberger, Plant Pathology Extension Associate

and Paul Vincelli, Extension Plant Pathologist

Figure 1: Scorch symptoms may develop between

veins (left) or along margins (right) of deciduous

plant leaves. (Photo: Left – Cheryl Kaiser, UK; Right

– Nicole Ward Gauthier, UK)

Figure 2: Needles of evergreen plants turn brown at the tips as result of leaf scorch. (Photo: University of Illinois Coopera-tive Extension, Bugwood.org)

Figure 3: Winter drying may lead to dried leaves with a brown coloration along margins or on needles. (Photo: Cheryl Kaiser, UK)

KY Fruit and Vegetable Conference to offer something for everyone. Want to get your farm off to a good

start in 2017? Then don’t miss the Kentucky Fruit and Vegetable Conference, scheduled for January 9th-

10th at Embassy Suites in Lexington. The conference will feature educational opportunities on production

and marketing that will benefit established growers and beginning farmers. Pre-conference sessions on

Sunday, January 8th, will include a Plasticulture Strawberry Short Course, and Vegetable and Tree and

Small Fruit Round Table discussions. Monday and Tuesday sessions will include the Grape & Wine Short

Course, vegetable production, tree and small fruit production, organic production, high tunnel and

greenhouse production, farmers markets and wholesale marketing, and a “What to Think About Before You

Plant” workshop brought to you by the Center for Crop Diversification. The workshop will feature decision

-making publications related to specialty crops, as well as a panel of growers and buyers from a variety of

market channels. The $40 conference registration fee includes a year’s membership in the Kentucky

Vegetable Growers Association, Kentucky State Horticultural Society or the Organic Association of

Kentucky, and entrance into the Grape & Wine Short Course and the What to Think About Before You

Plant workshop. The conference trade show will feature approximately 50 vendors. For more information,

visit the Center for Crop Diversification website at www.uky.edu/CCD/.

Ray Tackett

County Extension Agent for Horticulture

603 Millersburg Rd

Paris, KY 40361